Vara, who is also MP for North West Cambridgeshire, wrote: “With much sadness and regret I have submitted my letter of resignation as a Northern Ireland Minister to the Prime Minister. A copy of my letter is attached.
“It has been a joy and privilege to serve in the Northern Ireland Office and I will always cherish the fondest memories.”
He has held the ministerial post since July 2018.
In the letter, Vara states that he “cannot support the Withdrawal Agreement that has been agreed with the European Union”, adding that May’s deal “leaves the UK in a half-way house with no time limit on when we will finally be a sovereign nation”.
“We are a proud nation and it is a say day when we are reduced to obeying rules made by other countries who have shown that they do not have our best interests at hear,” Vara writes. “We can and must do better than this. The people of the UK deserve better.”